Evaporation sources

ABSTRACT

An evaporation device for depositing thin films of material in high vacua which includes means for supporting a substrate material on which the films are to be deposited, and a rotatable evaporation source.

United States Patent [72] Inventors Stanley Desmond Smith Reading; Frederick Stafford Ritchie, Newcastle upon Tyne, both of England [21 Appl. No. 858,304

[22] Filed Sept. 16, 1969 [45] Patented Dec. 7, 1971 [73] Assignee Sir Howard Grubb Parsons & Company Limited Newcastle upon Tyne, England by said Ritchie [32] Priority Dec. 2, 1968 [3 3] Great Britain [54] EVAPORATION SOURCES 3 Claims, 1 Drawing Fig.

521 u.s.c| .l

[51] Int. Cl C23c ll/00 [50] Field of Search ..1l8/4849.5; 219/271, 275; 13/21 [56] References Cited UNITED STATES PATENTS 2,341,827 2/1944 Sukumlyn 118/49 X 2,453,801 11/1948 Mattern 118/49 X 2,745,773 5/1956 Weimer 118/49 X 3,131,917 5/1964 Gessneret a1. 118/59X 3,375,804 4/1968 Rausch 118/49.1 X

Primary Examiner-Morris Kaplan Altarney- Holman & Stern ABSTRACT: An evaporation device for depositing thin films of material in high vacua which includes means for supporting a substrate material on which the films are to be deposited, and a rotatable evaporation source.

EVAPORATION SOURCES This invention relates to evaporation sources for use in high vacuum.

Such sources are commonly used for deposition of thin films under high vacuum, and one particular application is the deposition of thin films in the manufacture of multilayer interference filters. Such filters consist essentially of alternating layers of two materials with different indices of refraction. The filters are constructed by evaporating the materials onto a suitable substrate.

It is well known that in order to obtain a uniform deposit on the substrate, there should be relative rotation of the evaporation source and subtrate. Generally the evaporation source is held stationary while the substrate is rotated above the source. In some instances, however, it is not convenient to rotate the substrate especially when it is necessary to protect the substrate from thermal shock and/or close control of the substrate temperature is necessary.

The object of the present invention is to provide an improved evaporation source suitable for such purposes.

The invention consists in an evaporation device for depositing thin films of material in high vacua which includes means for supporting a substrate material on which the films are to be deposited, and a rotatable evaporation source.

The invention also consists in an evaporation device, wherein said means for supporting a substrate material includes a supporting plate suspended above said evaporation source.

The invention also consists in an evaporation device substantially as described herein with reference to the accompanying drawing which shows a device in accordance with the embodiment of the invention.

In carrying the invention into effect in the form illustrated by way of example in the drawing, an evaporation source device comprises a base ring I mounted and supported by rollers 2 on each of three fixed brackets 3 which in turn are located on baseplate 4.

Below the base ring and attached thereto is a drive ring 5 having on its periphery gear teeth which are engaged by a driving pinion 6. The pinion 6 is driven by a motor 17 through a shaft 7 passing through the baseplate 4.

Pillars 8 extend from the base ring and on these pillars are mounted sliprings 9, l0 and I]. The sliprings are mounted in spaced relation to the pillars and are spaced apart by bushes 12 of electrical insulating material.

Connected to sliprings l0 and 11 is an evaporation source 13 and connected to sliprings 9 and 10 is a further evaporation source 14.

The sliprings are supplied with alternating current electrical power through brushes 15. The brush housings and connections have been omitted for clarity.

The whole device is located in a vessel 16 which can have air evacuated therefrom.

The substrates 18 are located above the plane of rotation of the sources and in the center and top part of the vessel, the substrates 18 being mounted upon a supporting plate 19 suspended from the top of the vessel 16 by means of rods 20.

Whilst in the arrangement described two sources are used only one source can be used in which case only one pair of sliprings are required. Alternatively three or more sources can be used increasing the number of sliprings.

We claim:

1. An evaporation device for depositing thin films of material in high vacua, which includes means for supporting said mounting means including a rotatable slipring assembly comprising at least three sliprings, each source being supported by a member connected between a pair of sliprings and electrical brushes associated with the sliprings being provided to convey electrical power for activation of the sources.

2. An evaporation device as claimed in claim I, wherein said means for supporting a substrate material includes a supporting plate suspended above said evaporation sources.

3. An evaporation device for depositing thin films of material in high vacua comprising 'a vessel from which air can be evacuated and having therein means for supporting a substrate material on which the films are to be deposited, at least two rotatable evaporation sources each of which is arranged to be operated to deposit material independently of the other, means mounting each of said sources for movement, during operation of the source, along a circular path about an axis disposed generally perpendicular to the surface of said substrate material on which the films are to be deposited said mounting means including a member supporting each of said sources and connected between a pair of sliprings forming part of a rotatable slipring assembly, a base ring carrying the slipring assembly, means passing through the wall of the vessel for rotating the base ring, and electrical connections for feeding power by way of the sliprings for activation of said sources.

l i I i 

1. An evaporation device for depositing thin films of material in high vacua, which includes means for supporting a substrate material on which the films are to be deposited, at least two rotatable evaporation sources each of which is arranged to be operated to deposit material independently of the other, means mounting each of said sources for movement, during operation of the source, along a circular path about an axis disposed generally perpendicular to the surface of said substrate material on which the films are to be deposited, said mounting means including a rotatable slipring assembly comprising at least three sliprings, each source being supported by a member connected between a pair of sliprings and electrical brushes associated with the sliprings being provided to convey electrical power for activation of the sources.
 2. An evaporation device as claimed in claim 1, wherein said means for supporting a substrate material includes a supporting plate suspended above the said evaporation sources.
 3. An evaporation device for depositing thin films of material in high vacua comprising a vessel from which air can be evacuated and having therein means for supporting a substrate material on which the films are to be deposited, at least two rotatable evaporation sources each of which is arranged to be operated to deposit material independently of the other, means mounting each of said sources for movement, during operation of the source, along a circular path about an axis disposed generally perpendicular to the surface of said substrate material on which the films are to be deposited said mounting means including a member supporting each of said sources and connected between a pair of sliprings forming part of a rotatable slipring assembly, a base ring carrying the slipring assembly, means passing through the wall of the vessel for rotating the base ring, and electrical connections for feeding power by way of the sliprings for activation of the said sources. 